Dual Dopamine Derived Polydopamine Coated N‐Doped Porous Carbon Spheres as a Sulfur Host for High‐Performance Lithium–Sulfur Batteries

Abstract

Lithium–sulfur (Li–S) batteries are considered to be one of the most promising energy storage systems owing to their high energy density and low cost. However, their wide application is still limited by the rapid capacity fading. Herein, polydopamine (PDA)‐coated N‐doped hierarchical porous carbon spheres (NPC@PDA) are reported as sulfur hosts for high‐performance Li‐S batteries. The NPC core with abundant and interconnected pores provides fast electron/ion transport pathways and strong trapping ability towards lithium polysulfide intermediates. The PDA shell could further suppress the loss of lithium polysulfide intermediates through polar–polar interactions. Benefiting from the dual function design, the NPC/S@PDA composite cathode exhibits an initial capacity of 1331 mAh g−1 and remains at 720 mAh g−1 after 200 cycles at 0.5 C. At the pouch cell level with a high sulfur mass loading, the NPC/S@PDA composite cathode still exhibits a high capacity of 1062 mAh g−1 at a current density of 0.4 mA cm−2.

Sustainable Synthesis of N‐Doped Hollow Porous Carbon Spheres via a Spray‐Drying Method for Lithium‐Sulfur Storage with Ultralong Cycle Life

“…The reduction peak at around 2.2 V is related to the transformation from S 8 to long‐chain lithium polysulfide (Li 2 S n , 4≤ n ≤8), and the reduction peak at approximately 2.0 V is corresponding to the reduction of long‐chain lithium polysulfide to short‐chain lithium polysulfide (Li 2 S and Li 2 S 2 ) [51] . The oxidation peak at about 2.4 V is resulted in the reversible transformation from the lower order lithium polysulfide to long‐chain lithium polysulfide and S 8 [52] . Noting that the potential differences (Δ E ) between cathodic and anodic peaks of N‐HPCS/S are lower than those of HPCS/S, indicating the improved reaction reversibility and kinetics of N‐HPCS/S electrode caused by N‐doping.…”

Nitrogen-Doped Porous Carbon Nanosheets Strongly Coupled with Mo2C Nanoparticles for Efficient Electrocatalytic Hydrogen Evolution

“…Firstly, the dopamine self-polymerized on the surface of bulk MoS 2 to form a MoS 2 @PDA core-shell structure (Additional file 1: Figure S1b). Then, the core-shell structure MoS 2 @PDA was carbonized to form N-doped carbon film wrapped on the surface of MoS 2 , which was signed as MoS 2 @NC (Additional file 1: Figure S1c) [23, 24]. Finally, the mixture of the as-prepared MoS 2 @NC and KOH was placed into a tube furnace and reacted to acquire the final product: nitrogen-doped porous carbon nanosheets coupled with Mo 2 C nanoparticles (donated as Mo 2 C/NPC) (Additional file 1: Figure S1d).…”

Polydopamine-based nanoreactors: synthesis and applications in bioscience and energy materials

“…Apart from the advantages discussed above, sulfur containing nanoreactors with core/shell or porous structures exploit the mechanical flexibility of PDA for accommodating the volume changes of sulfur species during discharging and charging. A typical work demonstrating its multifunctional role was reported by Zhang et al 91 PDA-coated N-doped hierarchical porous carbon spheres (NPC@PDA) with a core-shell structure were applied as cathode materials (Figure 5b). The porous structure of PDA and N-doping of the carbon sphere core dramatically enhanced the chemical adsorption ability towards lithium polysulfides and the electrochemical reaction kinetics of sulfur, respectively.…”

“…89 Encapsulating sulfur into PDA-derived carbon nanoreactors has become a popular strategy to address the above issues through suppressing the polysulfide diffusion and building a conductive framework for electron/ion transport. [90][91][92][93] Compared to PDAderived carbon materials which provide mainly physical confinement for polysulfides, direct use of PDA has been found to be more efficient in adsorption of polysulfides via chemical confinement. The nitrogen and oxygen atoms with lone electron pairs in PDA can provide polar surfaces to trap polysulfide species; the strong chemical interactions between the nitrogen/oxygen atoms and lithium polysulfides can efficiently decrease their dissolution, thereby increasing sulfur utilization and improving the cycling stability.…”